Omega-shaped Geometries of Reflectarray Resonant Elements with Low Cross-polarization for Wideband and Dual-Polarization Use

This paper presents low cross-polarization single-layer reflectarray elements for dual-polarization use. These elements have an omega-shaped symmetrical structure to realize the cross-polarization reduction and also provide parallel linear reflection-phase properties with almost the same slop characteristics for the frequency, thereby achieving the desirable reflection phase range more than 360 degrees over the wide frequency range. To verify effectiveness of the proposed elements, a reflectarray antenna with an offset feed is constructed by them, and wideband frequency characteristics are also confirmed at Ku-band numerically and experimentally.